1. Field of the Invention
The invention relates to a device that reduces torsional vibration by reciprocation of a rolling body.
2. Description of Related Art
One example of this type of device is described in Japanese Patent Application Publication No. 2014-47805. The device includes a plate member that is attached to a crankshaft of an engine. A recessed accommodating portion that is formed in an annular shape is formed in the plate member. A plurality of mass bodies that reciprocate by fluctuations in transmitted torque are disposed in the accommodating portion. The mass bodies are connected by connection members that are disposed along opposite side surfaces of the mass bodies.
Also, Japanese Patent Application Publication No. 2013-148211 describes a torsional vibration reducing device including an inertial mass body composed of a first pendulum member and a second pendulum member. Connection members are provided on opposite side surfaces of each of the pendulum members. The connection members of the pendulum members are connected to each other via a spring.
In a configuration described in JP 2014-47805 A, since the connection members are disposed along the opposite side surfaces of the mass bodies, the opposite side surfaces of the mass bodies and the connection members possibly come into contact with each other. When the torque fluctuates, the mass bodies reciprocate. In this case, if the opposite side surfaces of the mass bodies and the connection members come into contact with each other, sliding friction occurs between the opposite side surfaces of the mass bodies and the connection members, and the sliding friction produces resistance to hinder the reciprocation of the mass bodies. As a result, damping performance is possibly deteriorated. Also, since the connection members are disposed along the side surfaces of the mass bodies, an axial length of the torsional vibration reducing device is possibly increased corresponding to a thickness of the connection members. The inconveniences may be also similarly caused in the invention described in JP 2013-148211 A.